I'm evaluating moving our aging infrastructure to Amazon's AWS and am trying to estimate costs. I know our current disk space requirements, bandwidth, and most of the other variables that will affect cost. The one that's got me stumped is IOPS on EBS volumes. My thought is to capture performance monitor data from our existing servers (using PolyMon), but I'm not sure which PhysicalDisk metrics match up with Amazon's IOPS count. My two guesses are Disk Reads/Writes or Average Disk Reads/Writes.